As a candle manufacturer, we often get asked about the safety of candles. In fact we've been asked everything from "Is it safe to burn candles indoors?" to "Is it safe to burn them around pet fish?" So we decided to investigate the key facts and fictions around candle safety...
The Internet is full of warnings about “toxic candles,” what’s going on?
It seems to have started back in 1974, when the United States Consumer Safety Protection Commission looked into the safety of putting lead into candle wicks to act as a stiffener. Lighting the candle would cause the lead to get into the air.
Airborne lead? That sounds dangerous!
Potentially, yes. Even small amounts of the substance can cause lead poisoning. And small children are particularly vulnerable, as they are still developing mentally and physically. Because of the danger, members of the National Candle Association voluntarily agreed to stop putting lead into candle wicks back in the 1970s.
So there’s no more lead in candle wicks?
Close to 100%, but not quite. The National Candle Association says that the likelihood of buying a lead-wicked candle in the U.S. is “very low.” But a paper written by the EPA in 2001 found that “candles with lead wicks have been found on the market and have been shown to emit lead when burned.”
How can I be sure?
The EPA found that most of the lead-wicked candles on the market were imported. The best bet is to buy U.S.-made candles, since imported candles may not always adhere to U.S. safety standards. You'll sometime see candle brands making a big deal out of their wicks being lead-free, but the reality is that even if we desperately wanted to buy lead wicks, we would struggle. In our experience as U.S. candlemakers, we have never seen lead or lead-reinforced wicks available for purchase.
The National Candle Association has a simple test you can do to see if a candle wick has a lead core: take a plain piece of paper and rub it on the tip of the unburned wick. If the wick leaves a gray mark on the paper, then it contains lead.
A wick that uses a lead core should leave a light grey mark, similar to what a pencil mark would look like (Credit: NCA)
Are there any other kinds of wicks I should be concerned about?
Nope! Most wicks in the U.S. are 100% cotton, though some might contain zinc or other stiffeners. The EPA has found that none of these substances have been shown to emit toxins in candle wicks.
So we’re safe on wicks. What about the candle wax?
As a refresher, wax is a flammable, carbon-containing solid that becomes liquid when heated above room temperatures; in short, it’s the fuel for the candle flame. We’ve written about the different waxes used for candles before. Most concerns center around paraffin wax, a commonly used candle wax derived from petroleum.
One 2009 study found that burning paraffin candles can release harmful chemicals such as toluene. But this study has been called into question by the National Candle Association, particularly because it has not been published in a scientific journal.
In our opinion, the main area of improvement the candle (and almost any other consumer product) industry needs to make is around being better for the planet rather than for us humans. Paraffin sucks mainly because it's generated from fossil fuels, less because it's harmful to humans.
What about candle soot?
A quick definition: candle soot is made up of impure carbon particles and is produced when there is incomplete combustion of the wax. Candle soot is also chemically different from soot produced by burning diesel, coal, and gasoline.
Candle smoke or "soot" is the carbon created from incomplete combustion.
Candle soot can damage property, but has not been shown to have any adverse health effects. To keep a candle from sooting, make sure to trim the wick to ¼” before burning.
What about fragrance?
In short, studies have proven inconclusive, and there isn’t a government agency responsible for giving a definitive answer since as it’s not considered a public health concern. There is a lot of misinformation online in this area. One example is recurring citation from a study on claimed dangers of limonene—a naturally occurring molecule in citrus fruits and mint, among other places. Some articles would have you believe that it must be avoided at all costs (taking it literally, we should avoid oranges at all costs since the oil in the peel is 98% limolene), and fundamentally misunderstand the concept of toxicity. From our experience, we’ve found the professional fragrance industry to be better than we expected in terms of safety testing, and we suggest sticking to companies that produce fragrances professionally and put them through IFRA safety testing (the industry standard for fragrance safety used by major fragrance houses, and Keap); as with most things in life, we also suggest practicing moderation.
What about fire safety?
Candle fires are pretty rare. According to the National Fire Prevention Agency, only 4% of all home fires from 2018-2022 were due to candles. There are some simple rules that, according to the U.S. Consumer Product Safety Commission, would eliminate most candle-related fires:
- Never leave a burning candle unattended.
- Never burn a candle on or near anything that might catch fire.
- Keep candles out of the reach of children and pets.
Follow these rules, and you can enjoy candles without worry.
But I still don’t know if it’s safe for my fish/dog/baby/cat/other?
We don’t think you need to lose sleep over this. Humans have being using candles for thousands of years. And the main health concerns connected to modern candles have been well addressed. With a little common sense and moderation, candles can be a fun and enjoyable part of your life.
People can of course have a personal allergy to any scent. There are a couple of very common misunderstandings around fragrance allergies:
1) Many people assume they are allergic to "all fragrance". Allergies are in fact related to a specific molecule(s) / compound(s). Some possible may be allergic to ingredients very commonly used in fragrances (e.g. vanillin) and therefore feel like they are allergic to anything scented, but there are 1000s of fragrance molecules and it's impossible to be allergic to them all (you come into contact with many in day to day life).
2) Man-made molecules are not more allergenic to naturally extracted ones. You can be allergic to molecules produced through either method, and in practice allergies are more common with naturals (in short because natural contain an uncontrollable mix of molecules, while synthetics are easier to regulate)
To summarize, candles can be enjoyed safely by buying U.S.-made, sticking to naturally-derived waxes (instead of paraffin), and by trimming the wick before each lighting. If you find yourself experiencing allergies, try higher quality fragrances and contact the manufacturer—many like us, will offer a replacement for free. We hope this puts your mind at ease!
Questions, ideas, candles! TheLab@KeapBK.com.
Further Reading
Why Coconuts make a Better Wax (Keap)
Fragrance Transparency: Naturals vs Synthetics (Keap)
Fragrance Transparency: Naturals vs Synthetics (Keap)
The EPA’s Study on Candle Safety (2001)
A Study on Candle Wax Emissions (2007)
Snopes’ article on Scented Candles (2016)
